A type of bacteria that’s overabundant in the nasal passages of people with hay fever may worsen symptoms. Targeting that bacteria may provide a way to rein in ever-running noses.
Hay fever occurs when allergens, such as pollen or mold, trigger an inflammatory reaction in the nasal passages, leading to itchiness, sneezing and overflowing mucus. Researchers analyzed the composition of the microbial population in the noses of 55 people who have hay fever and those of 105 people who don’t. There was less diversity in the nasal microbiome of people who have hay fever and a whole lot more of a bacterial species called Streptococcus salivarius, the team reports online January 12 in Nature Microbiology.
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S. salivarius was 17 times more abundant in the noses of allergy sufferers than the noses of those without allergies, says Michael Otto, a molecular microbiologist at the National Institute of Allergy and Infectious Diseases in Bethesda, Md. That imbalance appears to play a part in further provoking allergy symptoms. In laboratory experiments with allergen-exposed cells that line the airways, S. salivarius boosted the cells’ production of proteins that promote inflammation.
And it turns out that S. salivarius really likes runny noses. One prominent, unpleasant symptom of hay fever is the overproduction of nasal discharge. The researchers found that S. salivarius binds very well to airway-lining cells exposed to an allergen and slathered in mucus — better than a comparison bacteria that also resides in the nose.
The close contact appears to be what makes the difference. It means that substances on S. salivarius’ surface that can drive inflammation — common among many bacteria — are close enough to exert their effect on cells, Otto says.
Hay fever, which disrupts daily activities and disturbs sleep, is estimated to affect as many as 30 percent of adults in the United States. The new research opens the door “to future studies targeting this bacteria” as a potential treatment for hay fever, says Mahboobeh Mahdavinia, a physician scientist who studies immunology and allergies at Rush University Medical Center in Chicago.
But any treatment would need to avoid harming the “good” bacteria that live in the nose, says Mahdavinia, who was not involved in the research.
The proteins on S. salivarius’ surface that are important to its ability to attach to mucus-covered cells might provide a target, says Otto. The bacteria bind to proteins called mucins found in the slimy, runny mucus. By learning more about S. salivarius’ surface proteins, Otto says, it may be possible to come up with “specific methods to block that adhesion.”
Source link Recent reports suggest that an excess of a certain bacteria found in the nose could cause allergies to worsen.
Researchers from the University of California at Berkeley conducted a study to examine the connection between Staphylococcus aureus, a type of bacteria that lives in the nose, and the development of allergic skin sensitisation. They found that when mice were exposed to Staphylococcus aureus, their allergic responses were stronger than when compared to mice without the bacteria present.
This result implies that when humans are exposed to too much of this bacteria, it could make existing allergic responses worse. Scientists speculate that this occurs as the presence of Staphylococcus aureus leads to increased production of IgE antibodies, which are proteins that cause the body’s allergic reactions. Furthermore, they suggest that the presence of Staphylococcus aureus might make existing allergies more difficult to manage.
In order to reduce the amount of Staphylococcus aureus present in the nose and thus lower the risk of aggravated allergic responses, relevant clinical strategies need to be developed and implemented. These might involve techniques such as the use of medicines to reduce bacterial colonization, as well as counselling patients on the importance of basic hygiene measures.
Potential future investigations could also involve looking into different environmental factors, such as allergies and behaviour change, to further establish this correlation between Staphylococcus aureus and allergies.
In conclusion, the study highlights a potential link between an excess of Staphylococcus aureus found in the nose, and the worsening of allergy symptoms. This means that further research is needed to develop clinical strategies that reduce this bacteria and control the allergic responses of people with allergies.
